There is an updated pull request by ashiire against master on the mblaze repository

https://github.com/ashiire/mblaze ashiire-patch-1
https://github.com/leahneukirchen/mblaze/pull/232

improve named part/attachment detection
This will add filename detection for parts which specify Content-Disposition _without_ a filename parameter and Content-Type _with_ a name parameter. I'm not sure whether omitting this possibility was intentional, e.g. to adhere to standard, but messages which name their attachments in this way occur in the wild.

A patch file from https://github.com/leahneukirchen/mblaze/pull/232.patch is attached